Adaptive operation to mitigate specular reflections

Abstract

Methods, devices, and apparatus to adapt operating parameters for satellite signal reception and transmission by a wireless device to mitigate effects of fading due to specular reflections are described herein. The wireless device measures received signal power levels and compares characteristics of the measurements over an observation duration to at least one fading criteria to determine whether to operate in a normal or adaptive mode. While operating in the adaptive mode, the wireless device alternates between high performance mode time periods and low performance mode time periods. The wireless device indicates to a ground station associated with the satellite in which operating mode the wireless device is operating via an uplink data message transmitted during a data cycle at the start of a high or low performance mode time period. The ground station schedules data transmissions accordingly during subsequent data cycles of the high or low performance mode time periods.

What is claimed is: 
     
       1. A method for mitigating specular reflections, the method comprising:
 by a wireless device:
 measuring one or more fading properties of a signal received from a satellite, the signal including a direct path component and a specular reflected indirect path component; 
 comparing the one or more measured fading properties of the signal to at least one fading criteria; and 
 when the comparing satisfies the at least one fading criteria, configuring a wireless transceiver of the wireless device to operate in an adaptive mode that comprises alternating high performance time periods and low performance time periods. 
 
 
     
     
       2. The method of  claim 1 , wherein the at least one fading criteria comprises:
 a measurement duration; 
 a fading level; and 
 a fading periodicity. 
 
     
     
       3. The method of  claim 2 , wherein the comparing satisfies the at least one fading criteria when:
 a measurement duration satisfies a duration threshold; and 
 a fading level satisfies a fading level threshold and a fading periodicity satisfies a fading periodicity threshold. 
 
     
     
       4. The method of  claim 3 , wherein the fading level satisfies the fading level threshold when a difference between a peak level and a lowest level for two or more fades of the measurement duration equals or exceeds the fading level threshold. 
     
     
       5. The method of  claim 3 , wherein the fading periodicity satisfies the fading periodicity threshold when a time period between two or more successive fades of the measurement duration equals or falls below the fading periodicity threshold. 
     
     
       6. The method of  claim 1 , further comprising:
 by the wireless device:
 when the comparing does not satisfy the at least one fading criteria, configuring the wireless transceiver of the wireless device to operate in a normal mode. 
 
 
     
     
       7. The method of  claim 1 , further comprising:
 maintaining the wireless device in a currently configured mode when the at least one fading criteria is not satisfied. 
 
     
     
       8. The method of  claim 1 , further comprising:
 determining, by the wireless device, respective time durations of the high performance time periods and the low performance time periods based at least in part on a comparison of a predicted receive signal level from the satellite to a receive signal threshold. 
 
     
     
       9. The method of  claim 1 , further comprising:
 transmitting, by the wireless device to a ground station through an uplink communication link via the satellite during a first data interval of a first cycle of a high performance time period, a first message to indicate operation of the wireless device in a high performance mode during the high performance time period. 
 
     
     
       10. The method of  claim 1 , further comprising:
 transmitting, by the wireless device to a ground station through an uplink communication link via the satellite during a first data interval of a first cycle of a low performance time period, a second message to indicate operation of the wireless device in a low performance mode during the low performance time period. 
 
     
     
       11. The method of  claim 1 , wherein:
 downlink data transmission to the wireless device and/or uplink data transmission from the wireless device is allowed during the high performance time periods and disallowed during the low performance time periods. 
 
     
     
       12. The method of  claim 1 , wherein a downlink data transmission quantity and/or rate to the wireless device and/or uplink data transmission quantity and/or rate from the wireless device is higher during the high performance time periods than during the low performance time periods. 
     
     
       13. The method of  claim 1 , wherein downlink data transmission to and/or uplink data transmission from the wireless device uses higher modulation during one or more of the high performance time periods than during one or more of the low performance time periods. 
     
     
       14. The method of  claim 1 , wherein downlink data or uplink data comprises higher priority data during at least one high performance time period than during at least one low performance time period. 
     
     
       15. The method of  claim 1 , wherein downlink data or uplink data comprises higher quality of service (QoS) data during at least one high performance time period than during at least one low performance time period. 
     
     
       16. The method of  claim 1 , wherein the wireless device:
 operates in a normal power consumption mode during at least one high performance time period; and 
 operates in a reduced power consumption mode during at least one low performance time period. 
 
     
     
       17. A wireless device comprising:
 an antenna; and 
 processing circuitry communicatively coupled to the antenna and comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform actions that include:
 measuring one or more fading properties of a signal received from a satellite, the signal including a direct path component and a specular reflected indirect path component; 
 comparing the one or more measured fading properties of the signal to at least one fading criteria; and 
 when the comparing satisfies the at least one fading criteria, configuring a wireless transceiver of the wireless device to operate in an adaptive mode that comprises alternating high performance time periods and low performance time periods. 
 
 
     
     
       18. The wireless device of  claim 17 , wherein the actions further include:
 determining, by the wireless device, a first time duration associated with the high performance time periods and a second time duration associated with the low performance time periods based at least in part on a comparison of a predicted receive signal level from the satellite to a receive signal threshold. 
 
     
     
       19. The wireless device of  claim 17 , wherein the actions further include:
 transmitting, by the wireless device, during a first data interval of a first cycle of a high performance time period, a first message indicating operation of the wireless device in a high performance mode during the high performance time period; and 
 transmitting, by the wireless device, during a first data interval of a first cycle of a low performance time period, a second message indicating operation of the wireless device in a low performance mode during the low performance time period. 
 
     
     
       20. An apparatus configured for operation in a wireless device, the apparatus comprising processing circuitry comprising one or more processors and a memory storing instructions that, when executed by the one or more processors, cause the wireless device to perform actions that include:
 measuring one or more fading properties of a signal received from a satellite, the signal including a direct path component and a specular reflected indirect path component; 
 comparing the one or more measured fading properties of the signal to at least one fading criteria; and 
 when the comparing satisfies the at least one fading criteria, operating in an adaptive mode that comprises alternating high performance time periods and low performance time periods.